Being able to trade with that much leverage is dangerous for people.  I do think it should be allowed, because I believe in freedom of personal choice, but I don't think most traders are aware of how risky it is.  Especially when trading cryptocurrencies, which have got to be even more volatile than penny stocks.  It's so easy to either get a margin call or have your position wiped out if the market turns against you, and you could lose everything in the blink of an eye.

But most people I know who are into trading are gamblers at heart, and the potential to make outsized profits is also immense.  I'm sure lots of them have gotten rich trading on margin, but I'm also fairly sure that some of them have ended up in the poor house as a result.